[gdk-pixbuf] (8 commits) Non-fast-forward update to branch wip/hadess/split-loaders

[Emmanuele Bassi <ebassi src gnome org>]

The branch 'wip/hadess/split-loaders' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  c44d995... Add missing 2.40 versioning macros
  843b7a1... core: Split off the initialisation sections
  4405d02... core: Pass module_file path as an argument
  8c4e675... core: Add gdk_pixbuf_init_modules() for applications
  a606b62... build: Bump version to 2.39.1
  d152a47... core: Fix split docs line in features.h file

Commits added to the branch:

  5a670c4... docs: Update the contribution guide (*)
  a991b36... build: Use idiomatic pkg-config generation (*)
  d73be6c... Add missing 2.40 versioning macros
  0c6bd29... core: Split off the initialisation sections
  92a59c8... core: Pass module_file path as an argument
  fd1376b... core: Add gdk_pixbuf_init_modules() for applications
  4f2fb35... build: Bump version to 2.39.1
  bf6452b... core: Fix split docs line in features.h file

(*) This commit already existed in another branch; no separate mail sent